Polynucleotide molecules and the proteins encoded by the molecules, diagnostic and treatment methods for neurological disorders characterized by protein aggregation are provided. Genes are described herein that affect the misfolding of, and subsequent aggregation of, aggregation-prone proteins such as alpha-synuclein and have implications for the diagnosis and treatment of neurological diseases related to protein aggregation such as Parkinson's disease. Knockdown of expression of the genes described herein using RNAi results in alpha-synuclein protein aggregation in a C. elegans model of protein aggregation. Dopaminergic neuroprotection after overexpression of alpha-synuclein may also be provided by overexpression of proteins. Knowledge of genes relating to protein misfolding and aggregation provides powerful means to develop diagnostic screening methods, mutation analysis and drug design information for the development of novel therapeutic and neuroprotective compounds to treat neurodegenerative diseases such as Parkinson's disease.